Inbred corn line MNI1

ABSTRACT

An inbred corn line, designated MNI1, is disclosed. The invention relates to the seeds of inbred corn line MNI1, to the plants of inbred corn line MNI1 and to methods for producing a corn plant produced by crossing the inbred line MNI1 with itself or another corn line. The invention further relates to hybrid corn seeds and plants produced by crossing the inbred line MNI1 with another corn line.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a new and distinctive corninbred line, designated MNI1. There are numerous steps in thedevelopment of any novel, desirable plant germplasm. Plant breedingbegins with the analysis and definition of problems and weaknesses ofthe current germplasm, the establishment of program goals, and thedefinition of specific breeding objectives. The next step is selectionof germplasm that possess the traits to meet the program goals. The goalis to combine in a single variety or hybrid an improved combination ofdesirable traits from the parental germplasm. These important traits mayinclude higher yield, resistance to diseases and insects, better stalksand roots, tolerance to drought and heat, reduction of the time to cropmaturity and better agronomic quality. With mechanical harvesting ofmany crop, uniformity of plant characteristics such as germination andstand establishment, growth rate, maturity and plant and ear height isimportant.

[0002] Choice of breeding or selection methods depends on the mode ofplant reproduction, the heritability of the trait(s) being improved, andthe type of cultivar used commercially (e.g., F.sub.1 hybrid cultivar,pureline cultivar, etc.). For highly heritable traits, a choice ofsuperior individual plants evaluated at a single location will beeffective, whereas for traits with low heritability, selection should bebased on mean values obtained from replicated evaluations of families ofrelated plants. Popular selection methods commonly include pedigreeselection, modified pedigree selection, mass selection, and recurrentselection.

[0003] The complexity of inheritance influences choice of the breedingmethod. Backcross breeding is used to transfer one or a few favorablegenes for a highly heritable trait into a desirable cultivar. Thisapproach has been used extensively for breeding disease-resistantcultivars. Various recurrent selection techniques are used to improvequantitatively inherited traits controlled by numerous genes. The use ofrecurrent selection in self-pollinating crops depends on the ease ofpollination, the frequency of successful hybrids from each pollination,and the number of hybrid offspring from each successful cross.

[0004] Each breeding program should include a periodic, objectiveevaluation of the efficiency of the breeding procedure. Evaluationcriteria vary depending on the goal and objectives, but should includegain from selection per year based on comparisons to an appropriatestandard, overall value of the advanced breeding lines, and number ofsuccessful cultivars produced per unit of input (e.g., per year, perdollar expended, etc.).

[0005] Promising advanced breeding lines are thoroughly tested andcompared to appropriate standards in environments representative of thecommercial target area(s) for three years at least. The best lines arecandidates for new commercial cultivars; those elite in traits are usedas parents to produce new populations for further selection.

[0006] These processes, which lead to the final step of marketing anddistribution, usually take from eight to twelve years from the time thefirst cross is made. Therefore, development of new cultivars is atime-consuming process that requires precise forward planning, efficientuse of resources, and a minimum of changes in direction.

[0007] A most difficult task is the identification of individuals thatare genetically superior, because for most traits the true genotypicvalue is masked by other confounding plant traits or environmentalfactors. One method of identifying a superior plant is to observe itsperformance relative to other experimental plants and to a widely grownstandard cultivar. If a single observation is inconclusive, replicatedobservations provide a better estimate of its genetic worth.

[0008] The goal of plant breeding is to develop new, unique and superiorcorn inbred lines and hybrids. The breeder initially selects and crossestwo or more parental lines, followed by repeated selfing and selection,producing many new genetic combinations. The breeder can theoreticallygenerate billions of different genetic combinations via crossing,selfing and mutations. The breeder has no direct control at the cellularlevel. Therefore, two breeders will never develop the same line, or evenvery similar lines, having the same corn traits.

[0009] Each year, the plant breeder selects the germplasm to advance tothe next generation. This germplasm is grown under unique and differentgeographical, climatic and soil conditions, and further selections arethen made, during and at the end of the growing season. The inbred lineswhich are developed are unpredictable. This unpredictability is becausethe breeder's selection occurs in unique environments, with no controlat the DNA level (using conventional breeding procedures), and withmillions of different possible genetic combinations being generated. Abreeder of ordinary skill in the art cannot predict the final resultinglines he develops, except possibly in a very gross and general fashion.The same breeder cannot produce the same line twice by using the exactsame original parents and the same selection techniques. Thisunpredictability results in the expenditure of large research monies todevelop a superior new corn inbred line.

[0010] The development of commercial corn hybrids requires thedevelopment of homozygous inbred lines, the crossing of these lines, andthe evaluation of the crosses. Pedigree breeding and recurrent selectionbreeding methods are used to develop inbred lines from breedingpopulations. Breeding programs combine desirable traits from two or moreinbred lines or various broad-based sources into breeding pools fromwhich inbred lines are developed by selfing and selection of desiredphenotypes. The new inbreds are crossed with other inbred lines and thehybrids from these crosses are evaluated to determine which havecommercial potential.

[0011] Pedigree breeding is used commonly for the improvement ofself-pollinating crops or inbred lines of cross-pollinating crops. Twoparents which possess favorable, complementary traits are crossed toproduce an F₁. An F₂ population is produced by selfing one or severalF₁'s or by intercrossing two F₁'s (sib mating). Selection of the bestindividuals is usually begun in the F₂ population; then, beginning inthe F₃, the best individuals in the best families are selected.Replicated testing of families, or hybrid combinations involvingindividuals of these families, often follows in the F₄ generation toimprove the effectiveness of selection for traits with low heritability.At an advanced stage of inbreeding (i.e., F₆ and F₇), the best lines ormixtures of phenotypically similar lines are tested for potentialrelease as new cultivars.

[0012] Mass and recurrent selections can be used to improve populationsof either self- or cross-pollinating crops. A genetically variablepopulation of heterozygous individuals is either identified or createdby intercrossing several different parents. The best plants are selectedbased on individual superiority, outstanding progeny, or excellentcombining ability. The selected plants are intercrossed to produce a newpopulation in which further cycles of selection are continued.

[0013] Backcross breeding has been used to transfer genes for a simplyinherited, highly heritable trait into a desirable homozygous cultivaror inbred line which is the recurrent parent. The source of the trait tobe transferred is called the donor parent. After the initial cross,individuals possessing the phenotype of the donor parent are selectedand repeatedly crossed (backcrossed) to the recurrent parent. Theresulting plant is expected to have the attributes of the recurrentparent (e.g., cultivar) and the desirable trait transferred from thedonor parent.

[0014] Descriptions of other breeding methods that are commonly used fordifferent traits and crops can be found in one of several referencebooks (e.g., Allard, R. W. “Principles of Plant Breeding” John Wiley andSon, pp.115-161, 1960; Simmonds, 1979; Sneep et al., 1979; Fehr, 1987).

[0015] Proper testing should detect any major faults and establish thelevel of superiority or improvement over current cultivars. In additionto showing superior performance, there must be a demand for a newcultivar that is compatible with industry standards or which creates anew market. The introduction of a new cultivar will incur additionalcosts to the seed producer, the grower, processor and consumer; forspecial advertising and marketing, altered seed and commercialproduction practices, and new product utilization. The testing precedingrelease of a new cultivar should take into consideration research anddevelopment costs as well as technical superiority of the finalcultivar. For seed-propagated cultivars, it must be feasible to produceseed easily and economically.

[0016] Once the inbreds that give the best hybrid performance have beenidentified, the hybrid seed can be reproduced indefinitely as long asthe homogeneity of the inbred parent is maintained. A single-crosshybrid is produced when two inbred lines are crossed to produce the F₁progeny. A double-cross hybrid is produced from four inbred linescrossed in pairs (A×B and C×D) and then the two F₁ hybrids are crossedagain (A×B)×(C×D). Much of the hybrid vigor exhibited by F₁ hybrids islost in the next generation. Consequently, seed from hybrid varieties isnot used for planting stock.

[0017] Hybrid maize seed is typically produced by manual or mechanicaldetasseling. Alternate strips of two maize inbreds are planted in afield, and the pollen-bearing tassels are removed from one of theinbreds (female). Providing that there is sufficient isolation fromsources of foreign maize pollen, the ears of the detasseled inbred willbe fertilized only from the other inbred (male), and the resulting seedis therefore hybrid and will form hybrid plants.

[0018] The laborious, and occasionally unreliable, detasseling processcan be avoided by using cytoplasmic male-sterile (CMS) inbreds. Plantsof a CMS inbred are male sterile as a result of factors resulting fromthe cytoplasmic, as opposed to the nuclear, genome. Thus, thischaracteristic is inherited exclusively through the female parent inmaize plants, since only the female provides cytoplasm to the fertilizedseed. CMS plants are fertilized with pollen from another inbred that isnot male-sterile. Pollen from the second inbred may or may notcontribute genes that make the hybrid plants male-fertile.

[0019] There are several methods of conferring genetic male sterilityavailable, such as multiple mutant genes at separate locations withinthe genome that confer male sterility, as disclosed in U.S. Pat. Nos.4,654,465 and 4,727,219 to Brar et al. and chromosomal translocations asdescribed by Patterson in U.S. Pat. Nos. 3,861,709 and 3,710,511, allpatents referred to being incorporated by reference.

[0020] Another system useful in controlling male sterility makes use ofgametocides. Gametocides are not a genetic system, but rather a topicalapplication of chemicals. These chemicals affect cells that are criticalto male fertility. The application of these chemicals affects fertilityin the plants only for the growing season in which the gametocide isapplied (see Carlson, Glenn R., U.S. Pat. No. 4,936,904). Application ofthe gametocide, timing of the application and genotype specificity oftenlimit the usefulness of the approach.

[0021] Corn is an important and valuable field crop. Thus, a continuinggoal of plant breeders is to develop stable, high yielding corn hybridsthat are agronomically sound. The reasons for this goal are obviously tomaximize the amount of grain produced on the land used and to supplyfood for both animals and humans. To accomplish this goal, the cornbreeder must select and develop corn plants that have the traits thatresult in superior parental lines for producing hybrids.

SUMMARY OF THE INVENTION

[0022] According to the invention, there is provided a novel inbred cornline, designated MNI1. This invention thus relates to the seeds ofinbred corn line MNI1, to the plants of inbred corn line MNI1 and tomethods for producing a corn plant produced by crossing the inbred lineMNI1 with itself or another corn line. This invention further relates tohybrid corn seeds and plants produced by crossing the inbred line MNI1with another corn line.

[0023] The inbred corn plant of the invention may further comprise, orhave, a cytoplasmic factor, or other factor, that is capable ofconferring male sterility. So, the invention further comprises a malesterile form of the inbred. Parts of the corn plant of the presentinvention are also provided, such as e.g., pollen obtained from aninbred plant and an ovule of the inbred plant.

[0024] In one aspect, the present invention provides regenerable cellsfor use in tissue culture or inbred corn plant MNI1. The tissue culturewill preferably be capable of regenerating plants having thephysiological and morphological characteristics of the foregoing inbredcorn plant, and of regenerating plants having substantially the samegenotype as the foregoing inbred corn plant. Preferably, the regenerablecells in such tissue cultures will be embryos, protoplasts,meristematics cells, callus, pollen, leaves, anthers, roots, root tips,silk, kernels, ears, cobs, husk or stalks. Still further, the presentinvention provides corn plant regenerated from the tissue cultures ofthe invention.

[0025] Another objective of the invention is to provide methods forproducing other inbred corn plants derived from inbred corn line MNI1.Inbred corn lines derived by the use of those methods are also part ofthe invention.

[0026] The invention also relates to methods for producing a corn plantcontaining in its genetic material one or more transgenes and to thetransgenic corn plant produced by that method.

[0027] In another aspect, the present invention provides for single geneconverted plants of MNI1. The single transferred gene may preferably bea dominant or recessive allele. Preferably, the single transferred genewill confer such trait as male sterility, herbicide resistance, insectresistance, resistance for bacterial, fungal, or viral disease, malefertility, enhanced nutritional quality, and industrial usage. Thesingle gene may be a naturally occurring maize gene or a transgeneintroduced through genetic engineering techniques.

[0028] The invention further provides methods for developing corn plantin a corn plant breeding program using plant breeding techniqueincluding recurrent selection, backcrossing, pedigree breeding,restriction fragment length polymorphism enhanced selection, geneticmarker enhanced selection and transformation. Seeds, corn plant, andparties thereof produced by such breeding methods are also part of theinvention.

Definitions

[0029] In the description and tables which follow, a number of terms areused. In order to provide a clear and consistent understanding of thespecification and claims, including the scope to be given such terms,the following definitions are provided:

[0030] Allele. The allele is any of one or more alternative form of agene, all of which alleles relates to one trait or characteristic. In adiploid cell or organism, the two alleles of a given gene occupycorresponding loci on a pair of homologous chromosomes.

[0031] Backcrossing. Backcrossing is a process in which a breederrepeatedly crosses hybrid progeny back to one of the parents, forexample, a first generation hybrid F₁ with one of the parental genotypeof the F₁ hybrid.

[0032] Essentially all the physiological and morphologicalcharacteristics. A plant having essentially all the physiological andmorphological characteristics means a plant having the physiological andmorphological characteristics, except for the characteristics derivedfrom the converted gene.

[0033] Regeneration. Regeneration refers to the development of a plantfrom tissue culture.

[0034] Single gene converted. Single gene converted or conversion plantrefers to plants which are developed by a plant breeding techniquecalled backcrossing wherein essentially all of the desired morphologicaland physiological characteristics of an inbred are recovered in additionto the single gene transferred into the inbred via the backcrossingtechnique or via genetic engineering.

[0035] Predicted RM. This trait for a hybrid, predicted relativematurity (RM), is based on the harvest moisture of the grain. Therelative maturity rating is based on a known set of checks and utilizesconventional maturity such as the Comparative Relative Maturity RatingSystem or its similar, the Minnesota Relative Maturity Rating System.

[0036] MN RM. This represents the Minnesota Relative Maturity Rating (MNRM) for the hybrid and is based on the harvest moisture of the grainrelative to a standard set of checks of previously determined MN RMrating. Regression analysis is used to compute this rating.

[0037] Yield (Bushels/Acre). The yield in bushels/acre is the actualyield of the grain at harvest adjusted to 15.5% moisture.

[0038] Moisture. The moisture is the actual percentage moisture of thegrain at harvest.

[0039] GDU Silk. The GDU silk (=heat unit silk) is the number of growingdegree units (GDU) or heat units required for an inbred line or hybridto reach silk emergence from the time of planting. Growing degree unitsare calculated by the Barger Method, where the heat units for a 24-hourperiod are: GDU=((Max Temp+Min Temp)/2)−50 The highest maximum used is86° F. and the lowest minimum used is 500 F. For each hybrid, it takes acertain number of GDUs to reach various stages of plant development.GDUs are a way of measuring plant maturity.

[0040] Stalk Lodging. This is the percentage of plants that stalk lodge,i.e., stalk breakage, as measured by either natural lodging or pushingthe stalks determining the percentage of plants that break off below theear. This is a relative rating of a hybrid to other hybrids forstandability.

[0041] Root Lodging. The root lodging is the percentage of plants thatroot lodge; i.e., those that lean from the vertical axis at anapproximate 300 angle or greater would be counted as root lodged.

[0042] Plant Height. This is a measure of the height of the hybrid fromthe ground to the tip of the tassel, and is measured in centimeters.

[0043] Ear Height. The ear height is a measure from the ground to theear node attachment, and is measured in centimeters.

[0044] Dropped Ears. This is a measure of the number of dropped ears perplot, and represents the percentage of plants that dropped an ear priorto harvest.

[0045] Stay Green. Stay green is the measure of plant health near thetime of black layer formation (physiological maturity). A high scoreindicates better late-season plant health.

DETAILED DESCRIPTION OF THE INVENTION

[0046] Inbred corn line MNI1 is a yellow dent corn with superiorcharacteristics, and provides an excellent parental line in crosses forproducing first generation (F₁) hybrid corn. Inbred corn line MNI1 isbest adapted to the Central corn belt, Northcentral, Southwest andWestern regions of the USA and can be used to produce hybrids having arelative maturity of approximately 107 on the Comparative RelativeMaturity Rating System for harvest moisture of grain. Inbred corn lineMNI1 shows an excellent seedling vigor, an early pollen shed, excellentbrittle stalk resistance, excellent husk cover and above average staygreen.

[0047] MNI1 is similar to LH123, however there are numerous differencesincluding the fact that MNI1 flowers substantially earlier than LH123.Hybrids with MNI1 also are lower eared and have a stronger smuttolerance.

[0048] MNI1 has a plant height of 245 cm with an average ear insertionof 62 cm. The kernels are arranged in distinct and slightly curved rowson the ear. Heat units to 50% pollen shed are approximately 1450 and to50% silk are approximately 1491.

[0049] MNI1 is an inbred line with very high yield potential and verystrong stalk and roots in hybrids. For an inbred of its maturity, MNI1results in a lower ear position in hybrid combination. Often thesehybrids combinations results in plants which are of much better thanaverage overall health when compared to inbred lines of similarmaturity.

[0050] Some of the criteria used to select ears in various generationsinclude: yield, stalk quality, root quality, disease tolerance, lateplant greenness, late season plant intactness, ear retention, earheight, pollen shedding ability, silking ability, and corn borertolerance. During the development of the line, crosses were made toinbred testers for the purpose of estimating the line's general andspecific combining ability, and parallel evaluations were run in Franceand in the USA by the Champaign, Ill. Research Station. The inbred wasevaluated further as a line and in numerous crosses by the Champaignstation and other research stations across the Corn Belt. The inbred hasproven to have a good combining ability in hybrid combinations.

[0051] The inbred line has shown uniformity and stability for thetraits, as described in the following variety description information.It has been self-pollinated a sufficient number of generations withcareful attention to uniformity of plant type. The line has beenincreased with continued observation for uniformity. No variant traitshave been observed or are expected in MNI1.

[0052] Inbred corn line MNI1 has the following morphologic and othercharacteristics (based primarily on data collected at Kirkland, Ill. andChampaign, Ill). TABLES  1. TYPE: Dent  2. REGION WHERE DEVELOPED:France.  3. MATURITY: Days Heat Units From emergence to 50% of plants 641491 in silk: From emergence to 50% of plants 62.5 1450 in pollen: HeatUnits: = GDU = ((Max Temp + Min Temp)/2) − 50  4. PLANT: Plant Height totassel tip: 244.45 cm (Standard Deviation =    8.44) Ear Height to baseof top ear: 61.95 cm  (4.79) Average Length of Top Ear 17.26 cm  (0.67)Internode: Average number of Tillers: 0  (0) Average Number of Ears perStalk: 1  (0) Anthocyanin of Brace Roots: moderate  5. LEAF: Width ofEar Node Leaf: 9.6 cm  (0.40) Length of Ear Node Leaf: 85.39 cm  (2.70)Number of leaves above top ear: 5.75  (0.45) Leaf Angle (from 2nd Leafabove 68.55°  (3.08) ear at anthesis to Stalk above leaf): Leaf Color:Dark Green Munsell Code 5GY 4/4 Leaf Sheath Pubescence 4 (Rate on scalefrom 1 = none to 9 = like peach fuzz): Marginal Waves 5 (Rate on scalefrom 1 = none to 9 = many): Longitudinal Creases 6.5 (Rate on scale from1 = none to 9 = many):  6. TASSEL: Number of Lateral Branches: 8.05 (1.07) Branch Angle from Central Spike: 51.55  (5.37) Tassel Length(from top leaf 47.9 cm  (2.24) collar to tassel top): Pollen Shed 6.5(Rate on scale from 0 = male sterile to 9 = heavy shed): Anther Color:Light Green Munsell Code 2.5GY 8/4 Glume Color: Light Green Munsell Code5GY 7/6 Bar Glumes: absent  7a. EAR: (Unhusked Data) Silk Color (3 daysafter emergence): Light green Munsell Code 2.5GY 8/6 Fresh Husk Color(25 days after 50% silking): Light Green Munsell Code 5GY 7/8 Dry HuskColor (65 days after 50% silking): Light Green Munsell Code 2.5GY 8/6Position of Ear: upright Husk Tightness 1 (Rate on scale from 1 = veryloose to 9 = very tight): Husk Extension at harvest: short (ear exposed) 7b. EAR: (Husked Ear Data) Ear Length: 14.65 cm  (1.01) Ear Diameter atmid-point: 40.22 mm  (1.25) Ear Weight: 90.1 gm (12.44) Number of KernelRows: 15.7  (1.53) Kernel Rows: distinct Row Alignment: slightly curvedShank Length: 8.73 cm  (1.73) Ear Taper: average  8. KERNEL: (Dried)Kernel Length: 9.87 mm  (0.40) Kernel Width: 7.64 mm  (0.66) KernelThickness: 5.58 mm  (0.82) Round Kernels (Shape Grade): 76.46%  (9.36)Aleurone Color Pattern: homozygous Aleurone Color: colorless HardEndosperm Color: yellow (Munsell code 2.5Y 8/12) Endosperm Type: normalstarch Weight per 100 kernels 26.35 gm  (2.00) (unsized sample):  9.COB: Cob Diameter at Mid-Point: 26.21 mm  (1.01) Cob Color: Red Munsellcode 2.5YR 5/6 10. AGRONOMIC TRAITS: Stay Green 7 (at 65 days afteranthesis) (Rate on scale from 1 = worst to 9 = excellent) 0% DroppedEars (at 65 days after anthesis) 0% Pre-anthesis Brittle Snapping 0%Pre-anthesis Root Lodging 0% Post-anthesis Root Lodging (at 65 daysafter anthesis) Yield of Inbred Per Se 32.5 Bu/ (at 12-13% grainmoisture): Acre

Tables

[0053] In the tables that follow, the traits and characteristics ofinbred corn line MNI1 are given in hybrid combination. The datacollected on inbred corn line MNI1 is presented for the keycharacteristics and traits. The tables present yield test informationabout MNI1. MNI1 was tested in several hybrid combinations at numerouslocations, with two or three replications per location. Informationabout these hybrids, as compared to several check hybrids, is presented.The first pedigree listed in the comparison group is the hybridcontaining MNI1. Information for each pedigree includes:

[0054] 1. Mean yield in Qx/Ha of the hybrid across all locations (MeanYield) is shown in column 2.

[0055] 2. A mean for the percentage moisture (% Moist) for the hybridacross all locations is shown in column 3.

[0056] 3. A mean of the percentage of plants with stalk lodging (%Stalk) across all locations is shown in column 4.

[0057] 4. A mean of the percentage of plants with root lodging (% Root)across all locations is shown in column 5.

[0058] 5. A note on the stay green across all location from 1 (poor) to9 (good) is shown in column 6.

[0059] 6. A mean of the percentage of plants with head smut (% headsmut) across all locations is shown in column 7.

[0060] 7. Test weight is the grain density measured in kg per 100 l isshown in column 8.

[0061] 8. A mean of plant height in cm is shown in column 9. TABLE 1Overall Comparisons Hybrid vs. Check Hybrids Location: South of France,1998 Mean Stay % Head Test Plant Pedigree Yield % Moist % Stalk % RootGreen Smut Weight Height FR1064*MNI1 121.6 31.3 3 8 3 65.9 270 MNI1*SBB1118.0 30.1 4 7 2 61.7 280 LH227*MNI1 118.2 29.4 8 6 2 66.2 280MNI1*SGI742 121.5 30.5 5 7 5 63.7 255 At 14 Locations As Compared to:P3514 110.1 29.2 4 6 1 63 258 P3394 119.6 29.6 4 8 6 65.5 272 DK604117.4 29.7 5 8 1 61.4 268 LG2447 106.0 27.1 5 6 19  65.8 245 P3527 120.629.4 3 8 1 65.8 275

[0062] TABLE 2 Overall Comparisons Hybrid vs. Check Hybrids Location:South of France, 1999 Mean Stay % Head Test Plant Pedigree Yield % Moist% Stalk % Root Green Smut Weight Height FR1064*MNI1 115.5 29.5 7 2 8 470.1 276 MNI1*SBB1 120.3 27.4 7 3 7 4 68 285 LH227*MNI1 113.2 27.4 11  48 1 70 284 MNI1*SGI742 116.3 28.5 8 2 7 4 69 286 At 15 Locations AsCompared to: P3514  99.8 27.5 8 5 6 1 69 236 P34B15 117.7 27.4 7 3 7 371.2 289 P3394 111.4 27.2 11  8 7 4 69.8 258 DK604 116.1 26.9 8 8 7 367.7 275 LG2447 107.7 24.7 7 1 5 39  70.9 260 P3527 112.3 27.1 10  8 711  69.7 269

FURTHER EMBODIMENTS OF THE INVENTION

[0063] This invention is also directed to methods for producing a cornplant by crossing a first parent corn plant with a second parent cornplant, wherein the first or second corn plant is the inbred corn plantfrom the line MNI1. Further, both first and second parent corn plantsmay be from the inbred line MNI1. Therefore, any methods using theinbred corn line MNI1 are part of this invention: selfing, backcrosses,hybrid breeding, and crosses to populations. Any plants produced usinginbred corn line MNI1 as a parent are within the scope of thisinvention. Advantageously, the inbred corn line is used in crosses withother corn varieties to produce first generation (F₁) corn hybrid seedand plants with superior characteristics. Still further, this inventionis also directed to methods for producing an inbred maize lineMNI1-derived maize plant by crossing inbred maize line MNI1 with asecond maize plant and growing the progeny seed, and repeating thecrossing and growing steps with the inbred maize line MNI 1-derivedplant from 0 to 7 times.

[0064] As used herein, the term “plant” includes plant cells, plantprotoplasts, plant cell of tissue culture from which corn plants can beregenerated, plant calli, plant clumps, and plant cells that are intactin plants or parts of plants, such as pollen, flowers, kernels, ears,cobs, leaves, husks, stalks, and the like.

[0065] The present invention contemplates a corn plant regenerated froma tissue culture of an inbred (e.g. MNI1) or hybrid plant of the presentinvention. As used herein, the term “tissue culture” indicates acomposition comprising isolated cells of the same or a different type ora collection of such cells organized into parts of a plant. Exemplarytypes of tissue cultures are protoplasts, calli, plant clumps, and plantcells that can generate tissue culture that are intact in plants orparts of plants, such as embryos, pollen, flowers, leaves, stalks,roots, root tips, anthers, and the like. In a preferred embodiment,tissue culture is embryos, protoplast, meristematic cells, pollen,leaves or anthers. Means for preparing and maintaining plant tissueculture are well known in the art. As well known in the art, tissueculture of corn can be used for the in vitro regeneration of a cornplant. Tissue culture of corn is described in European PatentApplication, Publication No. 160,390, incorporated herein by reference.Corn tissue culture procedures are also described in Green and Rhodes,“Plant Regeneration in Tissue Culture of Maize”, Maize for BiologicalResearch (Plant Molecular Biology Association, Charlottesville, Va.1982), at 367-372. A study by Duncan et al., (1985), “The production ofcallus capable of plant regeneration from immature embryos of numerousZea Mays Genotypes”, Planta, 165 :322-332, indicates that 97 percent ofcultured plants produced calli capable of regenerating plants.Subsequent studies have shown that both inbreds and hybrids produced 91percent regenerable calli that produced plant. Other studies indicatethat non-traditional tissues are capable of producing somaticembryogenesis and plant regeneration. See, e.g., Songstad et al., (1988)“Effect of ACC (1-aminocyclopropane-1-carboxyclic acid), Silver Nitrate& Norbonadiene on Plant Regeneration From Maize Callus Cultures”, PlantCell Reports, 7:262-265; Rao et al., (1986)) “Somatic Embryogenesis inGlume Cultures”, Maize Genetics Cooperative Newsletter, No. 60, pp.64-65; and Conger et al., (1987) “Somatic Embryogenesis From CulturedLeaf Segments of Zea Maysa”, Plant Cell Reports, 6:345-347, thedisclosures of which are incorporated herein by reference. Regenerablecultures may be initiated from immature embryos as described in PCTpublication WO 95/06128, the disclosure of which is incorporated hereinby reference.

[0066] Thus, another aspect of this invention is to provide for cellswhich upon growth and differentiation produce the inbred line MNI1.

[0067] The present invention encompasses methods for producing a cornplant containing in its genetic material one or more transgenes and thetransgenic corn plant produced by that method.

[0068] The molecular techniques allow genetic engineering of the genomeof plants by adding or modifying foreign or endogenous genes (referredto here as transgenes) in such a manner that the traits of the plant canbe modified in a specific way. Plant transformation involves theconstruction of an expression vector comprising one or more gene undercontrol or operatively linked to a regulatory element (e.g. a promoter).Such vector can be used to provide transformed corn plants, usingtransformation methods as described hereafter to incorporate the gene orthe genes into the genetic material of the corn plant.

[0069] To facilitate the identification of transformed plant cells, thevector of this invention may include plant selectable markers.Selectable markers and uses are well known in the art and includeenzymes which provide for resistance to antibiotics such as gentamycin(Hayford et al., Plant Physiol. 86: 1216 (1988)), hygromycin (VandenElzen et al., Plant Mol. Biol., 5: 299 (1985)), kanamycin (Fraley etal., Proc. Natl. Acad. Sci. U.S.A., 80: 4803 (1983)), and the like.Similarly, enzymes providing for production of a compound identifiableby colour change such as GUS, (beta.-glucuronidase Jefferson, R. A.,Plant Mol. Biol. Rep. 5: 387 (1987)), are useful.

[0070] Genes included in expression vectors must be driven by anucleotide sequence comprising a regulatory element, for example, apromoter. Several types of promoters are now well known in thetransformation arts, as are other regulatory elements that can be usedalone or in combination with promoters.

[0071] As used herein “promoter” includes reference to a region of DNAupstream from the start of transcription and involved in recognition andbinding of RNA polymerase and other proteins to initiate transcription.A “plant promoter” is a promoter capable of initiating transcription inplant cells. “Tissue-specific” promoters initiate transcription only incertain tissues, such as a pollen-specific promoter from Zm13 (Guerreroet al., Mol. Gen. Genet.224: 161-168 (1993). “Inducible” promoter isunder environmental control, such as the inducible promoter from asteroid hormone gene, the transcriptional activity of which is inducedby a glucocorticosteroid hormone (Schena et al., Proc. NatI. Acad. Sci.U.S.A. 88: 0421 (1991)). Tissue-specific and inducible promoters are“non-constitutive” promoters. A “constitutive” promoter is a promoterwhich is active under most environmental conditions such as the 35Spromoter from CaMV (Odell et al., Nature 313: 810-812 (1985) or thepromoters from such genes as rice actin (McElroy et al., Plant Cell 2:163-171 (1990)).

[0072] These regulatory sequences will allow the expression of thetransgenes in the transformed cells, in the transformed plants. Thetransgenes may code for proteins including plant selectable markers butalso proteins adding a value trait to the crop such as agronomic,nutritional or therapeutic value or proteins conferring resistance todiseases and/or pathogens (e.g. bacterial, fungal, insect or herbicideresistance).

[0073] Several techniques, depending on the type of plant or plant cellto be transformed, are available for the introduction of the expressionconstruct containing a DNA sequence encoding an protein of interest intothe target plants. See, for example, Miki et al., “Procedures forIntroducing Foreign DNA into Plants” in Methods in Plant MolecularBiology and Biotechnology, Glick, B. R. and Thompson, J. E. Eds. (CRCPress, Inc., Boca Raton, 1993) pages 67-88. In addition, expressionvectors and in vitro culture methods for plant cell or tissuetransformation and regeneration of plants are available. See, forexample, Gruber et al., “Vectors for Plant Transformation” in Methods inPlant Molecular Biology and Biotechnology, Glick, B. R. and Thompson, J.E. Eds. (CRC Press, Inc., Boca Raton, 1993) pages 89-119.

[0074] Suitable methods of transforming plant or plant cells, herebyincorporated by reference, include microinjection, electroporation orAgrobacterium mediated transformation; Ti and Ri plasmids ofAgrobacterium tumefaciens and Agrobacterium rhizogenes, (both plantpathogenic soil bacteria), respectively, carry genes responsible forgenetic transformation of the plant. See Gruber et al., supra, Miki etal., supra.

[0075] Another applicable method of plant transformation ismicroprojectile-mediated transformation wherein DNA is carried on thesurface of microprojectiles and accelerated to penetrate plant cellwalls and membranes (Sanford, J. C., Physiol Plant 79: 206 (1990), Kleinet al., Biotechnology 6: 559-563 (1988)). In maize, several targettissues can be bombarded with DNA-coated microprojectiles in order toproduce transgenic plants, including, for example, callus (Type I orType II), immature embryos, and meristematic tissue.

[0076] Following transformation of maize target tissues, expression ofthe above-described selectable marker genes allows for preferentialselection of transformed cells, tissues and/or plants, usingregeneration and selection methods now well known in the art.

[0077] The transgenic inbred lines produced by the forgoing methodscould then be crossed, with another (non-transformed or transformed)inbred line, in order to produce a transgenic hybrid maize plant.

[0078] When the term inbred corn plant is used in the context of thepresent invention, this also includes any single gene conversions ofthat inbred. The term single gene converted plant as used herein refersto those corn plants which are developed by a plant breeding techniquecalled backcrossing wherein essentially all of the desired morphologicaland physiological characteristics of an inbred are recovered in additionto the single gene transferred into the inbred via the backcrossingtechnique. Backcrossing methods can be used with the present inventionto improve or introduce a characteristic into the inbred. The termbackcrossing as used herein refers to the repeated crossing of a hybridprogeny back to one of the parental corn plants for that inbred. Theparental corn plant which contributes the gene for the desiredcharacteristic is termed the nonrecurrent or donor parent. Thisterminology refers to the fact that the nonrecurrent parent is used onetime in the backcross protocol and therefore does not recur. The donorparent may, or may not be transgenic. The parental corn plant to whichthe gene or genes from the nonrecurrent parent are transferred is knownas the recurrent parent as it is used for several rounds in thebackcrossing protocol (Poehiman & Sleper, 1994, Fehr, 1987). In atypical backcross protocol, the original inbred of interest (recurrentparent) is crossed to a second inbred (nonrecurrent parent) that carriesthe single gene of interest to be transferred. The resulting progenyfrom this cross are then crossed again to the recurrent parent and theprocess is repeated until a corn plant is obtained wherein essentiallyall of the desired morphological and physiological characteristics ofthe recurrent parent are recovered in the converted plant, in additionto the single transferred gene from the nonrecurrent parent.

[0079] The selection of a suitable recurrent parent is an important stepfor a successful backcrossing procedure. The goal of a backcrossprotocol is to alter or substitute a single trait or characteristic inthe original inbred. To accomplish this, a single gene of the recurrentinbred is modified or substituted with the desired gene from thenonrecurrent parent, while retaining essentially all of the rest of thedesired genetic, and therefore the desired physiological andmorphological, constitution of the original inbred. The choice of theparticular nonrecurrent parent will depend on the purpose of thebackcross, one of the major purposes is to add some commerciallydesirable, agronomically important trait to the plant. The exactbackcrossing protocol will depend on the characteristic or trait beingaltered to determine an appropriate testing protocol. Althoughbackcrossing methods are simplified when the characteristic beingtransferred is a dominant allele, a recessive allele may also betransferred. In this instance it may be necessary to introduce a test ofthe progeny to determine if the desired characteristic has beensuccessfully transferred.

[0080] Many single gene traits have been identified that are notregularly selected for in the development of a new inbred but that canbe improved by backcrossing techniques. Single gene traits may or maynot be transgenic, examples of these traits include but are not limitedto, male sterility, corn endosperm, herbicide resistance, resistance forbacterial, fungal, or viral disease, insect resistance, male fertility,enhanced nutritional quality, industrial usage, yield stability andyield enhancement. These genes are generally inherited through thenucleus. Some known exceptions to this are the genes for male sterility,some of which are inherited cytoplasmically, but still act as singlegene traits. Several of these single gene traits are described in U.S.Pat. Nos. 5,777,196; 5,948,957 and 5,969,212, the disclosures of whichare specifically hereby incorporated by reference.

Industrial Applicability

[0081] The seed of inbred maize line MNI1, the plant produced from theinbred seed, the hybrid maize plant produced from the crossing of theinbred, hybrid seed, and various parts of the hybrid maize plant andtransgenic versions of the foregoing, can be utilized for human food orlivestock feed. They also may be used as a raw material in industry. Thefood uses of maize, in addition to human consumption of maize kernels,include both products of dry-milling (e.g., meal, flour) and wet-millingindustries (e.g., dextrose, starch).

[0082] As livestock feed, maize is primarily used for beef cattle, dairycattle, hogs, and poultry.

[0083] Starch Industry now uses maize and maize derived products invarious productions such as papers, chemistry, and pharmacology. Plantparts other than the grain of maize are also used in industry, e.g. cobsare used for fuel and to make charcoal.

Deposit Information

[0084] A deposit of the inbred corn seed of this invention is maintainedby AgReliant Genetics, 4640 East State Road 32, Lebanon, Ind. 46052.Access to this deposit will be available during the pendency of thisapplication to persons determined by the Commissioner of Patent andTrademarks to be entitled thereto under 37 CRF 1.14 and 35 USC 122. Uponallowance of any claims in this application, all restrictions on theavailability to the public of the variety will be irrevocably removed byaffording access to a deposit of at least 2.500 seeds of the samevariety with the American Type Culture Collection (ATCC), 10801University Boulevard, Manassas, Va. 20110.

[0085] Although the foregoing invention has been described in somedetail by way of illustration and example for purposes of clarity andunderstanding, it will be obvious that certain changes and modificationsmay be practiced within the scope of the invention, as limited only bythe scope of the appended claims.

What is claimed is:
 1. An inbred corn seed designated MNI1, wherein asample of said seed has been deposited under ATCC Accession number______.
 2. A corn plant or parts thereof, produced by growing the seedof claim
 1. 3. Pollen of the plant of claim
 2. 4. An ovule or ovules ofthe plant of claim
 2. 5. A corn plant, or part thereof, having all thephysiological and morphological characteristics of the corn plant ofclaim
 2. 6. The corn plant of claim 2, wherein said plant is malesterile
 7. A tissue culture of regenerable cells of a corn plant ofclaim
 2. 8. The tissue culture of claim 7, the cells or protoplasts ofthe tissue culture being from a tissue selected from the groupconsisting of protoplast and calli, wherein the regenerable cells arederived from meristematic cells, leaves, pollen, embryo, roots, roottip, anthers, silks, flowers, kernels, ears, cobs, husks, and stalks. 9.A corn plant regenerated from the tissue culture of claim 7, capable ofexpressing all the morphological and physiological characteristics ofinbred corn plant MNI1.
 10. A corn plant with all the physiological andmorphological characteristics of the corn inbred MNI1, wherein said cornplant is produced by a tissue culture process using the corn plant ofclaim 5 as the starting material for such a process.
 11. A method forproducing a hybrid corn seed comprising crossing a first inbred parentcorn plant with a second inbred parent corn plant and harvesting theresultant hybrid corn seed, wherein said first or second parent cornplant is the corn plant of claim
 2. 12. A hybrid corn seed produced bythe method of claim
 11. 13. A hybrid corn plant, or parts thereof,produced by growing said hybrid corn seed of claim
 12. 14. Corn seedproduced by growing said hybrid corn plant of claim 13 and harvestingthe resultant seed.
 15. A method for producing a hybrid corn seedcomprising crossing an inbred plant according to claim 2 with another,different corn plant.
 16. A hybrid corn seed produced by the method ofclaim
 15. 17. A hybrid corn plant, or its parts, produced by growingsaid hybrid corn seed of claim
 16. 18. Corn seed produced from saidhybrid corn plant of claim
 17. 19. A method for producing a MNI1-derivedcorn plant, comprising: a) crossing inbred corn line MNI1, a sample ofseed of said line having been deposited under ATCC accession number______, with a second corn plant to yield progeny corn seed; and b)growing said progeny corn seed, under plant growth conditions, to yieldsaid MNI1-derived corn plant.
 20. A MNI1-derived corn plant, or partsthereof, produced by the method of claim 19, said MNI1-derived cornplant expressing a combination of at least two MNI1 traits selected fromthe group consisting of: a relative maturity of approximately 102-112based on the the Comparative Relative Maturity Rating System for harvestmoisture of grain, excellent seedling vigor, early pollen shed,excellent brittle stalk resistance, excellent husk cover, above averagestay green and adapted to the Central Corn Belt, Northcentral, Southwestand Western regions of the United States.
 21. The method of claim 19,further comprising: c) crossing said MNI1-derived corn plant with itselfor another corn plant to yield additional MNI1-derived progeny cornseed; d) growing said progeny corn seed of step (c) under plant growthconditions, to yield additional MNI1-derived corn plants; and e)repeating the crossing and growing steps of (c) and (d) from 0 to 7times to generate further MNI1-derived corn plants.
 22. A further MNI1derived corn plant or parts thereof, produced by the method of claim 21,said MNI1 derived corn plant expressing a combination of at least twoMNI1 traits selected from the group consisting of: a relative maturityof approximately 102-112 based on the the Comparative Relative MaturityRating System for harvest moisture of grain, excellent seedling vigor,early pollen shed, excellent brittle stalk resistance, excellent huskcover, above average stay green and adapted to the Central Corn Belt,Northcentral, Southwest and Western regions of the United States. 23.The method of claim 19, still further comprising utilizing plant tissueculture methods to derive progeny of said MNI1-derived corn plant.
 24. Afurther MNI1-derived corn plant or parts thereof, produced by the methodof claim 23, said MNI1-derived corn plant expressing a combination of atleast two MNI1 traits selected from the group consisting of: a relativematurity of approximately 102-112 based on the the Comparative RelativeMaturity Rating System for harvest moisture of grain, excellent seedlingvigor, early pollen shed, excellent brittle stalk resistance, excellenthusk cover, above average stay green and adapted to the Central CornBelt, Northcentral, Southwest and Western regions of the United States.25. The corn plant, or parts thereof, of claim 2, wherein the plant orparts thereof have been transformed so that its genetic materialcontains one or more transgenes operably linked to one or moreregulatory elements.
 26. A method for producing a corn plant thatcontains in its genetic material one or more transgenes, comprisingcrossing the corn plant of claim 25 with either a second plant ofanother corn line, or a non-transformed corn plant of the line MNI1, sothat the genetic material of the progeny that result from the crosscontains the transgene(s) operably linked to a regulatory element. 27.Corn plants, or parts thereof, produced by the method of claim
 26. 28. Amethod for developing a corn plant in a corn plant breeding programusing plant breeding techniques which include employing a corn plant, orits parts, as a source of plant breeding material comprising: using thecorn plant, or its parts, of claim 2 as a source of said breedingmaterial.
 29. The corn plant breeding program of claim 28 wherein plantbreeding techniques are selected from the group consisting of: recurrentselection, backcrossing, pedigree breeding, restriction fragment lengthpolymorphism enhanced selection, genetic marker enhanced selection, andtransformation.
 30. A corn plant, or parts thereof, produced by themethod of claim 28, said corn plant expressing a combination of at leasttwo MNI1 traits selected from the group consisting of: a relativematurity of approximately 102-112 based on the the Comparative RelativeMaturity Rating System for harvest moisture of grain, excellent seedlingvigor, early pollen shed, excellent brittle stalk resistance, excellenthusk cover, above average stay green and adapted to the Central CornBelt, Northcentral, Southwest and Western regions of the United States.31. The corn plant of claim 5, further comprising a single geneconversion.
 32. The corn plant of claim 31, further comprising acytoplasmic factor conferring male sterility.
 33. The single geneconversion of the corn plant of claim 31, where the gene is selectedfrom the group consisting of: a transgenic gene, a dominant allele, anda recessive allele.
 34. The single gene conversion of the corn plant ofclaim 31, where the gene confers a characteristic selected from thegroup consisting of: herbicide resistance, insect resistance, resistanceto bacterial, fungal, or viral disease, male sterility, corn endosperm,and improved nutritional quality.
 35. A corn plant, or part thereof,wherein at least one ancestor of said corn plant is the corn plant ofclaim 2, said corn plant expressing a combination of at least two MNI1traits selected from the group consisting of: a relative maturity ofapproximately 102-112 based on the the Comparative Relative MaturityRating System for harvest moisture of grain, excellent seedling vigor,early pollen shed, excellent brittle stalk resistance, excellent huskcover, above average stay green and adapted to the Central Corn Belt,Northcentral, Southwest and Western regions of the United States.